Impact of Virtualization and High Utilization: A Case Study

One financial enterprise, which has been running Windows Virtual Server for several years, was able to dramatically reduce the number of servers thanks to virtualization. In this case the average utilization was about 5% when running one-server-one-application. Moving to a virtualized environment allowed this firm to consolidate enough applications on each server to raise the utilization to a consistent 80%. This also had some unexpected consequences.

Because the firm had been running at such low utilization they had standardized on very low cost, single-socket, 1U rack-mount x86-based servers. These had on-board disk drives for boot operations and temporary file storage. The life of these servers was generally three to four years without failure, resulting in a long refresh cycle.

These same servers are being used for the virtualized environment and still have boot images stored locally. The enterprise found that these systems continued to provide the performance required but that they were now seeing an increased failure rate for both the hard drives and the motherboard. An 80% utilization rate was causing these units to overheat and fail much more quickly than they had previously.

The enterprise has now settled on an 18-month refresh cycle for these servers. Because the servers are very low cost and virtualization dramatically reduced the number of servers required, the enterprise found that continuing to use these servers, even with the more rapid replacement cycle, was cost effective.

The trade-off was for a more frequent refresh cycle rather than going to more expensive servers. Moving to higher-end servers might bring the refresh cycle back up to the three-to-four year range but the extra costs for those servers was deemed not to be worth the extra life. By refreshing more often they are also able to take better advantage of the latest technology while still purchasing low-end, low-cost x86 servers.

To read up on steps you can take to take the heat off your physical servers, we recommend you download the full case-study below.